Ricoh FT7770 Service Manual page 58

30
April, '89
Drum Thermistor Unit
2.
The drum thermistor unit has two thermistors that detect the temperature of
the drum surface.
One (TH-1) is for the control of the drum heater, and the other (TH-2) is
for bias compensation.
Usually, these thermistors touch the drum surface. However, when the drum
stay is removed, they are separated from the drum surface by a release
mechanism.
This prevents the drum from being damaged when it is removed.
Related Service Call Condition: See FIELD MANUAL for details.
SC 2:
Drum Thermistor Failure
3: Low Drum Temperature
SC
4:
SC Drum Overheating
2-2